The method constituting the subject matter of the present invention is from the field of water filters. It relates more particularly to the field of ultrafiltration type membrane filters.
Modules including one or more bundles of hollow fibers stretched out parallel to each other and alongside each other and potted at both their ends are known in the art. With both ends potted and cut, the modules are used in external/internal filtration or vice-versa. Some are multi-bundle modules, the bundles being assembled with common potting of all the bundles. When they are used in external/internal filtration, air injection nozzles are disposed at the bottom of the peripheral bundles. The document EP-0 655 418 discloses an installation of this type.
Modules including one or more bundles of hollow fibers whose ends are potted at one end and free but closed individually at the other end are also known in the art. With one end potted, the fibers being plugged individually at the other end but not potted [sic]. The potted end is at the top in operation. These modules are used in external/internal filtration.
Modules including bundles of hollow fibers with the fibers disposed in a U-shape and bent at the bottom may also be cited.
Some modules use multiple bundles arranged in a casing, with a mechanical seal provided around the potting around the top of each bundle (generally by an O-ring). Air can be injected at the bottom of the module.
For all these types of modules, the bundles are either directly potted in a casing or demountable from the casing, the seal being provided by O-rings around the potting.
Bundles that are not housed in a pressure casing, but in a pool, the permeate being recovered by suction, are also used in the field of immersed membrane filters in particular. These modules generally use compressed air to agitate the bundles, whether this is with a vertical bundle potted at both ends, with air nozzles around the bundle, or with a horizontal bundle potted at both ends, the air being injected by auxiliary means at the bottom of the pool.
These various filters are complex and costly. They are also subject to problems of efficient operation, in particular of correct bubbling.